A New Printing Technology Sets Off a High-Stakes Race

In the athletic-wear department at J.C. Penney in Marlboro, Mass., a 4-by-4-foot sign hangs from the ceiling above an aisle of $70 white sneakers. "Hello down there!" it greets shoppers. "So glad you stopped by! You've gotta try the Nike Air Quest. It's super comfortable and lightweight too!"

The sign looks like a piece of foam board, but it's actually a high-tech gadget that uses electronic "ink" to display text. Penney is trying out the technology to see if electronic signs -- which can be...